Ascites

The pathologic accumulation of fluid in the peritoneal cavity

75% due to cirrhosis and portal hypertension

Analysis of the fluid
-Cell Count
-Albumin
-Total Protein
-Culture

Based on History and DDx (consider getting)
-Amylase
-Bilirubin
-Triglycerides
-Glucose
-Cytology

Serum ascites albumin gradient (SAAG)

SAAG= [Albumin in serum - Albumin in Ascitic fluid]

SAAG > 1.1 = Transudative (Portal HTN, Cirrhosis, Cardiac Disease)
SAAG < 1.1 = Exudative (Neoplasm, Infectious, GI and GU causes)

Ascitic fluid normally contains:
< 500 leukocytes/µL
< 250 polymorphonuclear neutrophils (PMN)/µL

Ascitic PMN counts > 250/µL suggests spontaneous bacterial peritonitis

Ascites with a low SAAG, high leukocyte count but low PMN count suggests either malignancy (such as lymphoma) or tuberculosis

Chylous Ascites 

Chylous ascites can be caused by impaired lymphatic drainage because of congenital lymphangiectasia or lymphatic duct injury or obstruction

• Milky appearance
• High concentrations of triglycerides
• Relatively high white blood cell count with a predominance of lymphocytes 

Biliary Ascites

Clinically associated with either injury to the biliary tree or as a complication of liver transplantation or Kasai portoenterostomy

• Bile-stained ascitic fluid
• High bilirubin concentrations

Pancreatic Ascites

Pancreatic ascites is associated with acute pancreatitis and would feature 

• Cloudy, chylous, or blood-tinged ascitic fluid
• High concentrations of amylase (Should also elevated in the serum)